Modular electrical system for device units

ABSTRACT

A modular electrical system (10) supplies power to and controls a plurality of electric motors (M 1 , M 2 , M 3 , M 4 ) associated with a plurality of drive units folding or extending rows in a telescopic seating system, comprising the motors (M 1 , M 2 , M 3 , M 4 ), a control panel (12) removably communicating with the motors (M 1 , M 2 , M 3 , M 4 ) directing incoming current to drive the motors (M 1 , M 2 , M 3 , M 4 ) in a predetermined direction, a dual receptacle (18) communicating with the control panel (12), and a switch (26) terminating in a plug (30) removably communicating with the dual receptacle (18).

This application is a continuation of application Ser. No. 08/109,332,filed Aug. 18, 1993 U.S. Pat. No. 5,374,878.

BACKGROUND OF THE INVENTION

This invention relates to an electrical system for transmitting power toa plurality of drive units which fold or extend rows of seats or benchesarranged in a telescopic seating system.

Various devices are known in the art for extending or retractingbleachers, such as may be found in an indoor athletic facility. U.S.Pat. No. 4,285,172 to Quigley teaches a powered drive apparatus whichfolds and unfolds rows of bleachers and which is adapted to fit almostentirely beneath a deck of the lowermost row. However, no electricalsystem for driving more than one apparatus at a time is disclosed. U.S.Pat. No. 3,052,929 to Busse discloses a power actuated bleacherassemblage and suggests using multiple motor units which aresimultaneously operated by a single reversing switch; however, theconnections between the switch and the units are not specified.

Typically, components of a motor driven bleacher assemblage, testedindividually but not as a system, are shipped to the installation site,requiring personnel to both erect the structure of the bleachers and toperform all wiring associated with connections to the motor units. Thisoften requires installation personnel to manually strip ends of wiresand establish electrical connections according to a set of instructions.This has proven time consuming, resulting in significant costs borne bythe owner of the installation site. Furthermore, such an owner must relyon the expertise of the installation personnel, who may not be aregistered electrician, thereby raising a question as to whether qualityof the electrical connections may be assured. Moreover, lack of testingcomponents of the motor driven units of the bleacher assemblage as asystem presents the risk that the components, although tested andapproved individually, may not perform as desired when comprising a partof an overall system.

SUMMARY OF THE INVENTION

It is an important object of the present invention to provide a modularelectrical system having power drive unit components which are assembledand tested as a system before shipment to an installation site.

It is a further object of the present invention to provide a modularelectrical system in which power drive units, a control panel, and apower source are all interconnected through plug-in type connections,thereby relieving installation personnel of all wiring work.

It is a further object of the present invention to provide a modularelectrical system which allows for installation to a wide variety ofbleacher configurations using only a limited number of standardcomponents.

It is a further object of the present invention to provide a modularelectrical system which can utilize two or more control panels.

It is a further object of the present invention to provide a modularelectrical system which allows for simple and reliable means forchanging the direction of travel of drive units to fold or extend rowsin a telescopic seating system.

These as well as other objects are accomplished by a modular electricalsystem for supplying power to a plurality of drive units designed tofold or extend rows in a telescopic seating system having a plurality ofelectric motors driving the drive units, a control panel removablycommunicating with the motors directing incoming current to drive themotors in a predetermined direction, a dual receptacle communicatingwith said the control panel, and a switch terminating in a plugremovably communicating with the dual receptacle. Thus, a user mayactuate the switch to drive the drive units together in a particulardirection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the principal components of a modularelectrical system constructed in accordance with a preferred embodimentof the present invention;

FIG. 2 is a schematic view of an exposed control panel;

FIG. 3 is an elementary diagram of an electrical circuit for a controlpanel in the modular electrical system constructed in accordance withthe preferred embodiment of the present invention.

DETAILED DESCRIPTION

In accordance with this invention, it has been found that a modularelectrical system may be provided which is simple to install and whereina user may simultaneously control a plurality of drive units with asingle control panel.

Referring to FIG. 1, the modular electrical system 10 generally includesa control panel 12 (FIG. 2) housed in a control enclosure 14. The system10 is designed to supply power to and control movement of a plurality ofmotors associated with drive units extending or folding a telescopicseating system. Although no drive units are shown herein, a drive unitto be used in system 10 is described fully in copending application Ser.No. 08/109,151, filed Aug. 18,1993, the disclosure of which is herebyincorporated by reference. The control panel 12 communicates throughleads 48 (FIG. 2) protruding from at its lower end to a plurality ofdrive unit electric motors M₁, M₂, M₃, M₄ at upper sockets of respectivereceptacles 41, 43, 45, and 49, and transmits power thereto supplied bypower source wire 16. A dual receptacle 18 communicates with the controlpanel 12 through wire 20 and is provided with an extend socket 22 and afold socket 24. A switch 26 connected by wire 28 to a plug 30 removablycommunicates with dual receptacle 18 through plug 30 at either extendsocket 22 or fold socket 24. Switch 26 activates the control panel 12 tocause the drive units to move in unison to either fold or extend atelescopic seating system, as will be more fully described herein.Motors M₄ and M₃ are interconnected by a lead 51 plugged into lowersockets of receptacles 41 and 43, while motors M₂ and M₁ are similarlyinterconnected by a lead 53 at lower sockets of receptacles 45 and 49.

The system 10 may be further provided with an extend limit switch 32communicating with control panel 12 through wire 34 which terminatespower to the control panel 12 when the plurality of drive units havefully extended the telescopic seating system. The extend limit switch 32is mechanically actuated by the bleachers and is placed in the vicinityof the highest bleacher row. Similarly, a fold limit switch 36communicating with the control panel 12 through a wire 38 may beprovided to terminate power to the control panel when the plurality ofdrive units have fully folded the telescopic seating system.

A wire 40 may lead from the control panel 12 for connection to asatellite panel (not shown) having identical structure to the controlpanel 12 and communicating with electric motors of additional driveunits. Through connections to be more fully described, the control panelcontrols the motors of these additional drive units, as well as motorsM₁ -M₄.

Referring to FIG. 2, an exposed control panel 12 is shown having a firstterminal block generally indicated at 42, a second terminal blockgenerally indicated at 44, a fold relay F, an extend relay E, and apower blocking relay B. An auxiliary relay 46 disposed adjacent to thepower blocking relay B energizes or deenergizes the remaining relays andthus the entire control panel 12. Additionally, a fuse block 47 may beincluded in part of the second terminal block 44.

As shown in FIG. 2, it may be desired to drive only two drive units.Accordingly, a plurality of wires are connected as shown at firstterminal block 42 and lead out to the drive units through a pair ofleads 48. In such an arrangement, jumpers such as those shown at 50 areattached to adjacent terminals in the first terminal block opposite theplurality of wires forming leads 48. Similarly, pluralities of wiresconnected to second terminal block 44 respectively form lead 20communicating with dual receptacle 18, lead 16 to a power source, lead38 communicating with fold limit switch 36, lead 34 communicating withextend limit switch 32, and a lead 40 communicating with a satellitepanel when more than four drive units are to be used. Lead 40 would beconnected to one of the terminals "sp" in the satellite panel. With thearrangement shown, one may drive two drive units with a single controlpanel 12.

Referring to FIG. 3, the electrical circuit 12a of the control panel 12is broken as shown at circuit breaker 62, which when closed supplies thecircuit 12a with a preferable amperage of 20 or 30 amps. The path ofcurrent through circuit 12a differs depending on whether plug 30 ofswitch 26 is plugged into extend socket 22 or fold socket 24 of dualreceptacle 18 (FIG. 1).

If plug 30 is plugged into extend socket 22, current flows throughcircuit 12a to drive the plurality of motors in a direction such thatsaid plurality of drive units move together to extend the telescopicseating system. When circuit breaker 62 and switch 26 are closed,current flows from node 1 through fuse 47 and proceeds across node 2 tofirst and second extend terminals 3 and 4, respectively, whereupon poweris supplied to block power relay B, energizing extend relay E connectedin parallel to block power relay B. This closes the normally-opencontacts 64, B₁, and B₂, as well as extend contacts E1 and E2. Extendlimit switch 32 being closed before full bleacher extension, currentflows from extend relay E to third extend terminal 11. Current alsoflows from node 2 across the now-closed contact B1, where at node 80 itbranches to both supply power to motor M₄ and to flow across thenow-closed extend contact E1, supplying power to motor M₃. Since contactF2 is closed, the current then travels across a wire 66 to energizemotor M₂, whereafter it travels up the "red" wire, across now-closedcontact E2, and energizes motor M₁ via the "black" wire. Thus, theplurality of drive units operate to extend the telescopic seating systemuntil the extend limit switch 32 is mechanically opened, terminatingpower to the circuit 12a.

If plug 30 is plugged into fold socket 24, current flows through circuit12a to drive the plurality of motors in a direction such that theplurality of drive units move together to fold the telescopic seatingsystem. When circuit breaker 62 and switch 26 are closed, current flowsfrom node 1 through fuse 47 and proceeds across node 2 to first andsecond fold terminals 3a and 4a, energizing power blocking relay B andthus the circuit 12a. Contacts 64, 66, B1, and B1 thus again close.Assuming a predetermined condition is satisfied between third and fourthfold terminals 4b and 31, respectively, current then travels throughthese terminals to third rung of the circuit 12a across the now-closedcontact 66 and fold limit switch 36, thereby energizing the fold relayF. This, in turn, closes contacts F1 and F2. Current travels from node 2across now-closed contact B1, whereupon at node 80 it branches to bothsupply power to motor M₄ and to flow across the now-closed contact F1(contact E1 being open). The current thus flows through the "red" linedown to energize motor M₂, thence proceeding through wire 66 to energizemotor M₃. The current then travels up the "white" line across now-closedcontact F2, proceeding to the "black" line to energize motor M₁. Thus,the drive units all are driven rearwardly to fold the telescopic seatingsystem until fold limit switch 36 is mechanically opened, terminatingpower to the circuit 12a.

Reversal of the motors M₁, M₂, M₃, M₄ is accomplished through changingthe direction of the fields generated by the windings in the motors.Preferably, a 1/4 hp, 120 V, split-phase electric motor is used for eachmotor M₁ -M₄, such a motor being available under Model No. 5K934 from W.W. Grainger Co. of Chicago, Ill.

It is thus seen that a modular electrical system may be provided whicheliminates the need for wiring by installation personnel by virtue ofthe several plug-together connections. Further, a wide variety oflayouts may be used while still minimizing the number of standard parts,providing the system of the present invention with a modular concept.

As the above description is merely exemplary in nature, being merelyillustrative of the invention, many variations will become apparent tothose of skill in the art. Such variations, however, are included withinthe spirit and scope of this invention as defined by the followingappended claims.

That which is claimed:
 1. An electrical system for supplying power to aplurality of drive unit motors, comprising:a control panel removablycommunicating with said plurality of drive unit motors directingincoming current to drive said plurality of drive unit motors, saidcontrol panel including a relay group comprising a block relay receivingcurrent from a power source upon closing of a switch to energize saidcontrol panel, an extend relay directing current to flow in a firstdirection through said plurality of drive unit motors, and a fold relaydirecting current to flow through said plurality of drive unit motors ina second direction opposite said first direction; a first terminal blockdisposed proximate a lower end of said control panel; a second terminalblock disposed proximate a top end of said control panel; a satellitepanel terminal located in said second terminal block; and a dualreceptacle communicating with said second terminal block; said switchterminating in a plug removably communicating with said dual receptacle;said first terminal block, said relay group, and said second terminalblock arranged in sequence from proximate said lower end of said controlpanel to proximate said top end of said control panel; whereby a usermay actuate said switch to drive said plurality of drive units togetherin a particular direction.
 2. The system set forth in claim 1 furthercomprising a satellite panel lead running from said control panel.